Abstract
The genetic diversity of Babesia gibsoni strains worldwide is currently poorly defined. The present study aimed at characterizing B. gibsoni strains in naturally infected dogs in Taiwan, using a combination of polymerase chain reaction (PCR) and sequence analysis of both 18S rDNA and the gene encoding thrombospondin-related adhesive protein (TRAP). Genomic DNA was extracted from 29 parasitemic dogs and the target genes were separately amplified, sequenced, and aligned with corresponding sequences available in GenBank. All 18S rDNA sequences (1,262 bp) amplified from the Taiwanese isolates were identical to each other and had very high similarity (99.9–100%) with previously reported B. gibsoni sequences. These results provided the first molecular evidence showing infection of dogs with B. gibsoni from Taiwan. On the other hand, a phylogenetic analysis based on the deduced amino acid sequence of the TRAP gene demonstrated that the Taiwanese isolates were closely related to strains previously identified from Okinawa Island, Japan, but genetically distinct from strains found in Honshu area of Japan and Jeju Island of South Korea. The divergence of TRAP among geographically dispersed strains examined in this study and others supports the conclusion that this gene is useful for molecular genotyping of B. gibsoni strains.
